ios - 快速缓存.. iOS FBApi

Question

我正在从 fbgraph api 获取数据并在 View 中显示。

获取代码如下。

 func fetchProfile(){
        let parameters = ["fields":"email, name, picture.type(large)"]
        FBSDKGraphRequest(graphPath: "me", parameters: parameters).startWithCompletionHandler { (connection, result, error) in
            if error != nil{
                print(error)
                return
            } else {
                print(result)
                self.nameLabel.text = result["name"] as? NSString as? String
                self.emailAddress.text = result["email"] as? NSString as? String
                if let picture = result["picture"] as? NSDictionary, data = picture["data"] as? NSDictionary, url = data["url"] as? String{
                    print("this is what yout fetch with \(url)")
                    self.imageView.sd_setImageWithURL(NSURL(string: url))
                }
           }
        }
    }

viewDidLoad 中的代码

 override func viewDidLoad() {
        super.viewDidLoad()
        self.imageView.clipsToBounds = true
        self.imageView.layer.masksToBounds = true
        self.imageView.layer.cornerRadius = self.imageView.frame.height/2
        self.fetchProfile() 
 }

每当应用程序运行并开始显示时，大约需要 1.5 秒才能显示所有内容。您是否可以通过任何方式缓存此数据，因此无论何时出现屏幕，您都不必等待 2.0 秒，因为它会自动显示为 View 显示为其缓存。因为它是第一个出现的 View

Answer 1

您可以将这些内容保存在 NSUserDefaults 中，这样您就可以毫不延迟地轻松显示此信息。数据将在从 FBGraphAPI 获取真实数据后更新。

  func fetchProfile(){
    let defaults = NSUserDefaults.standardUserDefaults()
    if let _ = userDefaults.valueForKey("userName") {
        self.nameLabel.text = (userDefaults.valueForKey("userName") as? String)!
    }
    if let _ = userDefaults.valueForKey("userEmail") {
        self.emailAddress.text = (userDefaults.valueForKey("userEmail") as? String)!
    }
    let parameters = ["fields":"email, name, picture.type(large)"]
    FBSDKGraphRequest(graphPath: "me", parameters: parameters).startWithCompletionHandler { (connection, result, error) in
        if error != nil{

        } else {
            let userName: String! = result["name"] as? NSString as? String
            defaults.setObject(userName, forKey: "userName")
            self.nameLabel.text = userName
            let userEmail: String! = result["email"] as? NSString as? String
            defaults.setObject(userEmail, forKey: "userEmail")

            if let picture = result["picture"] as? NSDictionary, data = picture["data"] as? NSDictionary, url = data["url"] as? String{
                defaults.setObject(data!, forKey: "userPictureData")
                self.imageView.sd_setImageWithURL(NSURL(string: url))
            }
       }
    }
}